The present invention relates generally to infrared drying apparatus and, more particularly, to such apparatus wherein a wall having a heating radiator is arranged along a textile fabric processing run for drying a traveling textile fabric.
Representative examples of conventional infrared drying apparatus of the aforementioned type are disclosed in published West German patent application S No. 22 990/82a, 34, and laid-open West German patent application DE-OS No. 14 60 660. The apparatus in the former application provides a swivel mounting for its radiators to permit movement between positions facing toward and away from the material to be treated and further provides a switching arrangement for deactivating the radiators when facing away from the traveling material, thereby to avoid possible damage to the traveling material as well as to adjacent components of the apparatus whenever the material travel is stopped. As will be understood, whenever the apparatus is restarted, the radiators must again be re-heated to their desired operating temperature and, to accommodate the required time for re-heating, the material web is accelerated to optimal traveling speed in relation to the heating of the radiators in order to achieve uniform drying treatment of the material. As will be understood, this necessity limits the overall production output and efficiency of the drying apparatus.
Another disadvantage of conventional infrared drying equipment lies in the manner by which the radiators are heated. Typically, the radiators of conventional drying apparatus are designed originally for heating either by electrical current or by combustible gas. Generally, purchasers of such drying equipment choose the means of heating which utilizes the energy source which is most economical overall within the area in which the apparatus is to be operated. However, the costs of the different forms of energy can vary considerably over the course of any given day, from day-to-day, and at differing times throughout the year, and may also vary from one country to the next. Accordingly, it is advantageous to have the capability of selectively heating an infrared drying apparatus with either gas or electricity, depending upon which form of energy is most cost-efficient at any given time. Unfortunately, to accomplish any such change with conventional drying equipment requires the replacement of either the entire machine or at least its basic heating components which, in turn, necessitates a considerable capital investment as well as considerable set-up labor and down time.
In contrast, the present invention provides an infrared drying apparatus capable of being selectively heated as desired by either gas or electricity and enabling the change between such energy types to be accomplished without ceasing or slowing operation of the machine.